Q. I have used Google's Picasa photograph software for many years across several different PCs, resulting in my account being peppered with duplicate images. Can I delete them in one go?

A. Picasa is excellent for managing a photographic collection. It is able to detect potential multiple images, and offer deletion, but image by image not in a single click. There is free software that will provide bulk deletion, of which more later, but first Picasa. Use Picasa to backup your images before doing anything, just in case! Next, open Picasa, click on Tools/Experimental/Show duplicate files. Picasa will then scan your PC, and any attached drives, and list those that it thinks may be duplicates. Delete them as necessary, making sure that you keep one copy! For the courageous, there is the free VisiPics tool, which will scan, locate and delete "similar" images as well as obvious duplicates.

Q. I have a collection of increasingly elderly digital photographs, and video camera tapes, and am concerned that as technology moves on I shall eventually be unable to see them. How can I avoid them becoming obsolete?

A. This obsolescence is unavoidable unfortunately. Businesses deal with it by transferring data from older formats to newer ones regularly, and we need to do the same domestically. Your choices currently are DVD disk (but for how much longer?), online in one of the numerous Cloud services, USB sticks and external hard drives. I use two external hard drives. Notice that I said two external drives. Never leave yourself with only one copy of important files!

Q. I want to upload a photograph of myself to my membership profile on a website. The website asks that the image be no larger than 100Kb in file size, and have dimensions not exceeding 500 x 200 pixels. My camera takes much larger pictures than this. How can I resize them?

A. In answering this, I am assuming that you have not installed any image editing software and have only that which came with your operating system. It is surprisingly simple using these basic tools that came with your computer. On a Windows PC, right-click on the picture's icon, select "Open with" and choose Paint, the native Windows image editor. In Windows 7 or 8, click on the Home tab, and then Resize. In Windows XP, click on Image, then Attributes. In the box that opens up, make sure that "Pixels" is selected. In Windows 7 and 8, also make sure that "Maintain aspect ratio" is selected to avoid distorting the picture, and then enter the desired number of pixels for either the horizontal of vertical axis and Windows will calculate the other. In Windows XP, you will have to do a little arithmetic and supply both axes. Now save the image with a new name so that you still have the original image available. You can check the file size of the new image by right-clicking on its icon, and then selecting Properties. If it is still over 100Kb, resize it again using a smaller pixel count. On a Mac computer, open the image with the Preview program, then select Adjust Size from the Tools menu to reduce the image's dimensions. Verify the new size by highlighting the file and pressing the Command and "i" keys together.

Q. My Windows XP computer will no longer open JPEG/JPG image files that are attached to e-mails. Trying to open them just produces gobbledygook. How can I open them properly?

A. Windows has to make “associations” between file formats and the preferred software to open them. It is likely that you have installed a photo-editing program that won't work properly with your e-mail program. This is simple to sort out. Go to Windows Explorer and select any saved JPEG image. Right-click on it and select Open with, then Choose Program. To restore the original Windows default association, select Windows Picture and Fax Viewer, and tick the box that asks if you want to always use that program.

Q. I have a lot of 35mm negatives from the 1960s-1980s period which are in good condition, whilst the original photographs from them have faded and the colours have degraded. Is it possible to make digital copies from the negatives to store on my computer and print as required?

A. Yes it is, and it need not cost a lot depending on what equipment and software you have already. Many modern scanners, including those that are part of all-in-one printers, are of sufficient quality to be able to scan directly from 35mm negatives. If your scanner is an old one, or a bottom of the range all-in-one, then you may be able to buy a 35mm adaptor for it, but obviously try a direct scan first to see if the result is adequate. If it is not, there are specific negative slide scanners available. One that is spoken highly of is the AgfaPhoto AFS3 Negative Slide Scanner at around £60. You will find similar devices on Amazon, and eBay, from around £50 upwards new. Having scanned the negatives, you may want to retouch the scans of any that are damaged, or adjust their colours. Most scanners, general purpose or specific negative scanners, come with only basic editing software. If you need something more powerful, then you might consider buying Adobe Photoshop Elements for about £60.

Q. Is there any free software that will help me to clean up marks and scratches on old photographs and transparencies that I have scanned?

A. There are several such products. The one that I would recommend is the Polaroid Dust and Scratch Removal Software. Find it at http://www.tinyurl.com/7kg4jk6. It is old and not guaranteed to work with Windows Vista or Windows 7, but it is very effective. (Avoid the blandishments to download other items during the download process!) Open a scanned image with it, and it will analyse it and highlight areas for repair. Just accept, and let it go to work, which may take several minutes for each image.